Abstract

The Nile Tilapia, Oreochromis niloticus was exposed to Paraquat for 24 h so as to monitor its effects on the fish’s haematology, and general behaviours. The haematological parameters estimated include haemoglobin, mean cell haemoglobin, mean cell haemoglobin concentration, packed cell volume, mean cell volume, erythrocyte sedimentation rate and white and red blood cell counts. The hepatosomatic index was measured for different concentrations of Paraquat exposed. Results showed that the hepatosomatic index was decreasing with increasing concentration of Paraquat. Haemoglobin, mean cell haemoglobin, mean cell haemoglobin concentration and erythrocyte sedimentation rate were observed to be negatively related to concentration of Paraquat. Packed cell volume, white blood cell count (WBC), red blood cell count (RBC) showed positive relationship with concentration while mean cell volume was not significantly changing with change in concentration of Paraquat.

Key words: Oreochromis niloticus, Paraquat, herbicide, haematology, hepatosomatic, index, biological responses.